In semiconductor manufacturing, various tools or devices may be used to monitor the fabrication processes. For example, an off-line, high speed camera or a video recorder is utilized to monitor the shape of a liquid stream or a mist from a nozzle during fabrication processes in order to determine if variation occurs in applying the liquid stream or mist. Images of shape variation, if any, are captured by the off-line, high speed camera or the video recorder but are not sent for analysis in real time. Operation of the nozzle may not be ceased when variation is detected.